There are known many anti corrosive paints containing rust resisting pigments. Among them, zinc rich paint which contains a large amount of zinc powder and a binder is widely used for temporary rust resisting paint of large steel structures, such as ships, bridges and the like, because of its excellent rust resistance. It is believed that the rust resistance of the zinc rich paint is brought about from the sacrificial corrosion of zinc powder caused by an electro-chemical reaction with steel, and from the shut-off of water and oxygen due to the corrosion product of zinc powder.
However, a zinc rich paint has some defects. Although, increased amounts of zinc powder increase the sacrificial corrosion so as to enhance rust resistance, it also increases the white rust of such zinc powder so as to reduce the adhesion properties when an over-coating composition is coated thereon. If the amount of zinc powder is lowered, the
(A) 10 to 25% by weight of a organic solvent type binder having an ignition loss of not more than 33% by weight, PA1 (B) 40 to 70% by weight of zinc powder, PA1 (C) 5 to 50% by weight of an inorganic oxide pigment which has been heated at not less than 500.degree. C. up to an ignition loss of 3% by weight;
the amounts of the components (A), (B) and (C) being based on the dried film.